摘要
自愈合混凝土中微胶囊的分布具有随机性,叠加混凝土的非均质特性,使得微胶囊的受力状态具有统计学特征。针对混凝土中微胶囊受力状态实测不便的问题,采用混凝土细观数值实验的方法,通过PFC2D颗粒流离散元软件建立混凝土细观数值模型,根据宏观物理实验获得的应力应变曲线标定细观参数,进而开展混凝土细观数值实验。通过混凝土细观数值试件砂浆颗粒之间的接触力来分析微胶囊力学状态的统计特征,实验结果表明:法向接触拉力和压力的平均值分别为12.24和6.36 mN;标准差为23.07和25.57 mN;75%的法向接触拉力和压力分别位于10.09和11.90 mN以下,90%的法向接触拉力和压力分别位于20.42和24.51 mN以下,这与微胶囊受力状态的实测数据基本吻合。基于混凝土细观数值实验来分析自愈合微胶囊受力状态的方法具备应用前景,作为实测方法的补充,为微胶囊在混凝土中受力状态的获取及跨尺度研究提供了有效路径。
The distribution of microcapsules in self-healing concrete is random, and the stress state of microcapsules is statistically significant due to the heterogeneity of concrete. In order to solve the problem that it is difficult to measure the stress state of microcapsules in concrete, the concrete meso numerical model is established by PFC 2D particle flow discrete element software using the method of concrete meso numerical experiment. The mesonumerical model of concrete is calibrated according to the stress-strain curve obtained from the macroscopic physical experiment, and then the concrete meso numerical experiment is carried out. The statistical characteristics of the mechanical state of microcapsules are analyzed by the contact force between mortar particles of concrete meso numerical specimens. Experimental results show that the average values of normal contact tension and pressure are 12.24 and 6.36 mN, respectively;standard deviation is 23.07 and 25.57 mN;75% of the normal contact tension and pressure are below 10.09 and 11.90 mN, respectively;and 90% of the normal contact tension and pressure are below 20.42 and 24.51 mN respectively;which is basically consistent with the measured data of the stress state of microcapsules. The method of analyzing the stress state of self-healing microcapsules based on concrete meso numerical experiments has application prospects. As a supplement to the measured method, it provides an effective path for obtaining the stress state of microcapsules in concrete and cross-scale research.
作者
沈璐
洪鹤轩
蔡浚璟
SHEN Lu;HONG Hexuan;CAI Junjing(Institute of Marine and Civil Engineering,Dalian Ocean University,Dalian 116023,China)
出处
《实验技术与管理》
CAS
北大核心
2022年第9期71-75,共5页
Experimental Technology and Management
基金
辽宁省教育厅2021年度科学研究经费面上项目(LJKZ0719)
大连市科技创新基金项目(2021JJ11CG001)
辽宁省本科普通高校向应用型转变示范专业建设项目(辽教函[2017]779号)
大连海洋大学第三届“蔚蓝英才工程”资助项目(大海大校发[2018]156号)。
关键词
混凝土
自愈合
微胶囊
细观数值实验
受力状态
统计特征
concrete
self-healing
microcapsules
meso numerical experiment
stress state
statistical characteristics
作者简介
沈璐(1982-),男,辽宁大连,博士,副教授,主要研究方向为混凝土细观数值模拟,shenlu1982@163.com。
